Table 1.
Descriptive characteristics of the first breast cancer among 1-year survivors of a first primary breast cancer in 12 SEER registries, 1992–2016
| Calendar period of first breast cancer diagnosis | |||||
|---|---|---|---|---|---|
| Overall | 1992–1997 | 1998–2003 | 2004–2009 | 2010–2015 | |
| Characteristics of the first breast cancer | N = 419,818 | N = 89,052 | N = 107,103 | N = 107,828 | N = 115,835 |
| Overall, % | 100.0 | 21.2 | 25.5 | 25.7 | 27.6 |
| Year of diagnosis, mean years (SD) | 2004.0 (6.8) | 1994.6 (1.7) | 2000.5 (1.7) | 2006.5 (1.7) | 2012.5 (1.7) |
| Age at diagnosis, years, % | |||||
| < 40 | 5.9 | 6.7 | 6.1 | 5.8 | 5.3 |
| 40 to < 50 | 20.4 | 20.7 | 20.8 | 21.4 | 18.8 |
| 50 to < 60 | 26.1 | 23.0 | 26.7 | 27.5 | 26.6 |
| 60 to < 70 | 24.3 | 23.4 | 21.9 | 23.6 | 27.9 |
| ≥ 70 | 23.3 | 26.2 | 24.6 | 21.7 | 21.4 |
| Age at diagnosis, mean years (SD) | 58.8 (12.7) | 59.2 (13.1) | 58.8 (12.9) | 58.4 (12.6) | 59.0 (12.2) |
| Stage at diagnosis, % | |||||
| I | 50.7 | 50.9 | 50.9 | 50.2 | 50.7 |
| II | 36.0 | 33.8 | 35.4 | 36.7 | 37.7 |
| III | 13.3 | 15.4 | 13.7 | 13.1 | 11.6 |
| Histology, % | |||||
| Ductal | 75.4 | 73.4 | 72.3 | 76.3 | 79.1 |
| Lobular | 8.3 | 7.7 | 8.1 | 8.1 | 9.3 |
| Mixed | 7.1 | 5.7 | 9.1 | 7.8 | 5.6 |
| Other | 9.2 | 13.3 | 10.5 | 7.8 | 6.1 |
| ER status, % | |||||
| Positive | 73.1 | 62.0 | 68.6 | 76.4 | 82.8 |
| Negative | 18.6 | 20.2 | 18.6 | 19.8 | 16.0 |
| Borderline/unknown | 8.3 | 17.7 | 12.8 | 3.7 | 1.2 |
| Initial treatment receipt, % | |||||
| Surgerya | |||||
| None | 2.0 | – | 1.2 | 1.7 | 3.1 |
| BCS/unilateral mastectomy | 87.9 | – | 91.3 | 89.5 | 83.4 |
| Contralateral prophylactic mastectomy | 7.3 | – | 2.9 | 6.8 | 11.8 |
| Unknown | 2.8 | – | 4.6 | 2.0 | 1.7 |
| Radiation therapy | |||||
| Yes | 54.2 | 45.0 | 55.3 | 56.8 | 58.0 |
| No/unknown | 45.8 | 55.1 | 44.7 | 43.2 | 42.1 |
| Chemotherapy | |||||
| Yes | 40.5 | 31.3 | 41.9 | 45.0 | 42.0 |
| No/unknown | 59.5 | 68.8 | 58.1 | 55.0 | 58.0 |
| Hormone therapy | |||||
| Yes | 42.9 | 32.5 | 37.4 | 43.2 | 55.6 |
| No/unknown | 57.1 | 67.5 | 62.6 | 56.8 | 44.4 |
| HER2 statusb, % | |||||
| Positive | 14.5 | – | – | – | 14.5 |
| Negative | 80.6 | – | – | – | 80.6 |
| Borderline/unknown | 4.9 | – | – | – | 4.9 |
| Breast cancer subtypeb,c, % | |||||
| HR+/HER2+ | 10.2 | – | – | – | 10.2 |
| HR+/HER2− | 70.3 | – | – | – | 70.3 |
| HR−/HER2+ | 4.3 | – | – | – | 4.3 |
| HR−/HER2− (Triple negative) | 10.2 | – | – | – | 10.2 |
| Unknown | 5.0 | – | – | – | 5.0 |
SEER, Surveillance, Epidemiology, and End Results; ER, estrogen receptor; BCS, breast conserving surgery; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; PR, progesterone receptor
aInformation on initial surgery was available for breast cancers diagnosed from 1998+ (N = 330,766)
bHER2 status was routinely collected in 2010+. Estimates include first breast cancers diagnosed from 2010 to 2015 and followed through 2016 (N = 115,835)
cHR+ = ER+ and/or PR+; HR− = ER− and PR−